This section provides background information related to the present disclosure which is not necessarily prior art.
Many switched-mode power supplies have a tight output voltage regulation, especially on transient response or dynamic loadings of a system. Designers may implement a very high voltage feedback closed-loop gain to contain the transient voltage responses of the output within allowable limits.
With increasing efficiency requirements of power supplies, synchronous rectification is being widely used to increase efficiency of power supplies. During light load applications, synchronous rectification may be disabled to avoid reverse currents, for burst modes on circuits that utilize cross regulation, and to increase efficiency especially on LLC converters when operating frequency is higher.
Once synchronous rectifiers are enabled, their voltage drop may abruptly change from a body diode drop to almost zero, which may introduce a voltage overshoot at an output terminal of the power supply that exceeds an allowable limit.